Viscoelastic properties of healthy achilles tendon are independent of isometric plantar flexion strength and cross-sectional area

AbstractThe Achilles tendon (AT) is larger and stiffer in males compared to females. AT stiffness is determined by length differences during loading. However, as some collagen fibres run transversely, changes in cross-sectional area (CSA) are also expected. The study investigates the gender differences of AT-CSA during maximal voluntary isometric contraction (MVIC).Fifteen males and fifteen females were positioned prone on the isokinetic dynamometer with knee extended and ankle flexed 90°. AT-CSA [mm2] from rest to MVIC during plantar flexion was sonographically assessed. AT-CSA maximal deformation [mm2] was subtracted by CSAMVIC–CSArest. AT-CSA compliance [mm2/Nm] and strain [%] were calculated by dividing the CSA deformation [mm2] by peak torque [Nm] and CSA at rest [mm2], respectively. Gender differences were assessed by an independent sample t-test with Bonferroni correction (α=0.01).AT-CSA dimensions at rest (p=0.001) and contraction (p=0.001) as well peak torque (p=0.001) were statistically significant higher in males (54.4±5.1 mm2, 53.7±5.1 mm2, 120.1±26.8 Nm) compared to females (46.2±7.0 mm2, 43.4±6.9 mm2, 86.9±21.6 Nm). AT-CSA deformation (p=0.000) strain (p=0.000) and compliance (p=0.000) were found to be statistically significant higher in females (–2.8±0.9 mm2, –6.2±2.0%, –0.033±0.018 mm2/Nm) compared to males (–0.8±1.8 mm2, –1.4±3.3%, –0.007±0.008 mm2/Nm).During loading, the AT also deforms at the transverse level by reducing its CSA. CSA reduction was higher in females, indicating also higher CSA compliance compared to males. Higher CSA compliance might indicate higher adaptability towards loading and might be discussed as a protective factor.

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Contribution of Achilles tendon mechanical properties to torque steadiness in persons with transfemoral amputation

Prosthetics and Orthotics International ◽

10.1177/0309364620966431 ◽

2020 ◽

pp. 030936462096643

Author(s):

Anis Toumi ◽

Rowan Smart ◽

Dimitri Elie ◽

Jennifer Bassement ◽

Sébastien Leteneur ◽

...

Keyword(s):

Achilles Tendon ◽

Coefficient Of Variation ◽

Maximal Voluntary Contraction ◽

Plantar Flexion ◽

Voluntary Contraction ◽

Cross Sectional Area ◽

Sectional Area ◽

Transfemoral Amputation ◽

Cross Sectional ◽

Tendon Mechanics

Background: How Achilles tendon mechanics and plantar flexion strength and torque steadiness are altered in the intact leg of persons with trauma-related amputation is unknown. Understanding Achilles tendon mechanics following amputation will further inform rehabilitation approaches to enhance posture, balance, and force control. Objective: Conduct a pilot study to quantify plantar flexion maximal voluntary contraction torque, torque steadiness, and Achilles tendon mechanics in persons with unilateral trauma-related transfemoral amputation and controls without amputation. Study design: Cross-sectional study. Methods: Isometric plantar flexion maximal voluntary contractions were performed with the intact leg of ten males with transfemoral amputation (48 ± 14 years) and the dominant leg of age-matched male controls without amputation. Torque steadiness was calculated as the coefficient of variation in torque over 6 s during submaximal tracking tasks (5%, 10%, 25%, 50%, and 75% maximal voluntary contraction). Achilles tendon elongation and cross-sectional area were recorded with ultrasound to calculate strain, stress, and stiffness. Results: Maximal voluntary contraction and torque steadiness did not differ between persons with amputation (90.6 ± 31.6 N m, 3.7 ± 2.0%) and controls (95.8 ± 26.8 N m, 2.9 ± 1.2%; p > 0.05). Tendon stiffness (21.1 ± 18.2 N/mm) and strain (5.2 ± 1.3%) did not differ between groups ( p > 0.05). Tendon cross-sectional area was 10% greater in persons with amputation leading to 29% lower stress ( p = 0.021). Maximal voluntary contraction was a predictor of a lower coefficient of variation in torque ( R2 = 0.11, p < 0.05). Conclusion: Persons with trauma-related transfemoral amputation do not differ in plantar flexion maximal voluntary contraction and torque steadiness of the intact leg compared with controls without amputation. Larger tendon cross-sectional area reduces stress and enables distribution of force across a greater area.

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Achilles Tendon Cross-Sectional Area Changes during Maximal Voluntary Isometric Plantar-Flexion Contraction in Healthy Individuals

Medicine & Science in Sports & Exercise ◽

10.1249/01.mss.0000493304.08944.13 ◽

2014 ◽

Vol 46 ◽

pp. 47

Author(s):

Gerrit Hain ◽

Michael Cassel ◽

Konstantina Intziegianni ◽

Frank Mayer

Keyword(s):

Achilles Tendon ◽

Plantar Flexion ◽

Cross Sectional Area ◽

Sectional Area ◽

Healthy Individuals ◽

Cross Sectional ◽

Flexion Contraction

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Cross-sectional area of psoas major muscle and hip flexion strength in youth soccer players

European Journal of Applied Physiology ◽

10.1007/s00421-012-2335-7 ◽

2012 ◽

Vol 112 (10) ◽

pp. 3487-3494 ◽

Cited By ~ 7

Author(s):

Yoshihiro Hoshikawa ◽

Tomomi Iida ◽

Nozomi Ii ◽

Masataka Muramatsu ◽

Yoshiharu Nakajima ◽

...

Keyword(s):

Cross Sectional Area ◽

Soccer Players ◽

Sectional Area ◽

Cross Sectional ◽

Youth Soccer ◽

Psoas Major Muscle ◽

Psoas Major ◽

Hip Flexion ◽

Flexion Strength

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Patients with Achilles Tendon Rupture Have a Degenerated Contralateral Achilles Tendon: An Elastography Study

BioMed Research International ◽

10.1155/2018/2367615 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Qianru Li ◽

Qi Zhang ◽

Yehua Cai ◽

Yinghui Hua

Keyword(s):

Achilles Tendon ◽

Axial Strain ◽

Achilles Tendon Rupture ◽

Cross Sectional Area ◽

Control Group ◽

Computer Assisted ◽

Study Group ◽

Sectional Area ◽

Cross Sectional ◽

The Mean

Purpose. To evaluate differences of Achilles tendon (AT) hardness and morphology between asymptomatic tendons in patients with acute AT ruptures on the contralateral side and asymptomatic tendons in healthy people by using computer-assisted quantification on axial-strain sonoelastography (ASE). Methods. The study consisted of 33 asymptomatic tendons in 33 patients (study group) and 34 tendons in 19 healthy volunteers (control group). All the tendons were examined by both ASE and conventional ultrasound. Computer-assisted quantification on ASE was applied to extract hardness variables, including the mean (Hmean), 20th percentile (H20), median (H50) and skewness (Hsk) of the hardness within tendon, and the ratio of the mean hardness within tendon to that outside tendon (Hratio) and three morphological variables: the thickness (THK), cross-sectional area, and eccentricity (ECC) of tendons. Results. The Hmean, Hsk, H20, H50, and Hratio in the proximal third of the tendon body in study group were significantly smaller than those in control group (Hmean: 0.43±0.09 vs 0.50±0.07, p=0.001; Hsk: -0.53±0.51 vs -1.09±0.51, p<0.001; H20: 0.31±0.10 vs 0.40±0.10, p=0.001; H50: 0.45±0.10 vs 0.53±0.08, p<0.001; Hratio: 1.01±0.25 vs 1.20±0.23, p=0.003). The THK and cross-sectional area of tendons in the study group were larger than those in the control group (p<0.05). Conclusions. As a quantitative objective method, the computer-assisted ASE reveals that the asymptomatic ATs contralateral to acute rupture are softer than those of healthy control group at the proximal third and the asymptomatic tendons in people with rupture history are thicker, larger, and rounder than those of normal volunteers especially at the middle and distal thirds of AT body.

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Sex Differences in the Morphological and Mechanical Properties of the Achilles Tendon

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18178974 ◽

2021 ◽

Vol 18 (17) ◽

pp. 8974

Author(s):

Xini Zhang ◽

Liqin Deng ◽

Songlin Xiao ◽

Lu Li ◽

Weijie Fu

Keyword(s):

Mechanical Properties ◽

Achilles Tendon ◽

Maximum Voluntary Contraction ◽

Voluntary Contraction ◽

Cross Sectional Area ◽

Morphological Properties ◽

Sectional Area ◽

Cross Sectional ◽

Force Peak ◽

Strain Stress

Background: Patients with Achilles tendon (AT) injuries are often engaged in sedentary work because of decreasing tendon vascularisation. Furthermore, men are more likely to be exposed to AT tendinosis or ruptures. These conditions are related to the morphological and mechanical properties of AT, but the mechanism remains unclear. This study aimed to investigate the effects of sex on the morphological and mechanical properties of the AT in inactive individuals. Methods: In total, 30 inactive healthy participants (15 male participants and 15 female participants) were recruited. The AT morphological properties (cross-sectional area, thickness, and length) were captured by using an ultrasound device. The AT force–elongation characteristics were determined during isometric plantarflexion with the ultrasonic videos. The AT stiffness was determined at 50%–100% maximum voluntary contraction force. The AT strain, stress, and hysteresis were calculated. Results: Male participants had 15% longer AT length, 31% larger AT cross-sectional area and 21% thicker AT than female participants (p < 0.05). The plantarflexion torque, peak AT force, peak AT stress, and AT stiffness were significantly greater in male participants than in female participants (p < 0.05). However, no significant sex-specific differences were observed in peak AT strain and hysteresis (p > 0.05). Conclusions: In physically inactive adults, the morphological properties of AT were superior in men but were exposed to higher stress conditions. Moreover, no significant sex-specific differences were observed in peak AT strain and hysteresis, indicating that the AT of males did not store and return elastic energy more efficiently than that of females. Thus, the mechanical properties of the AT should be maintained and/or improved through physical exercise.

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